Survivors may suffer mental health problems following disasters, particularly posttraumatic stress disorder (PTSD) and depressive symptoms. However, few studies have explored longitudinal processes of co-occurring PTSD and depressive symptoms among adolescent survivors and their associated predictors and consequences. The present study examines the codevelopment of both symptoms postearthquake using a 10-year cohort. A total of 1,357 senior high school students reported PTSD and depressive symptoms at 6, 12, 18, and 24 months after the 2008 Wenchuan earthquake. Self-report measures were also used to evaluate earthquake exposure, negative life events, social support, and trait resilience. At the 10-year follow-up (T10y), 799 participants reported their quality of life (QoL) online and 744 of them provided available data. A parallel-process latent class growth analysis was used to identify trajectories. Multinominal logistic and linear regressions were used, respectively, to analyze the predictors and consequences of these trajectories. Three comorbid trajectories were found: a resilient group (56.7%), a vulnerable group (33.3%), and a chronic high-risk group (9.9%). Gender, injury/missing/killed of family members, witnessing of traumatic sciences, negative life events, social support, and trait resilience were significant predictors of vulnerable and chronic high-risk groups. Finally, adolescents in these two groups were more likely to experience poorer QoL in adulthood. The results highlight the heterogeneity of depression-PTSD comorbidities among adolescent survivors. They also emphasize PTSD-depression symptoms predictors and their adverse impacts on life outcomes in adulthood. Individualized interventions should be provided for adolescents affected by natural disasters, especially those in the vulnerable and higher risk groups. (PsycInfo Database Record (c) 2023 APA, all rights reserved).